Operating instructions

I [mA]

I 1

I 2

Fmax

0 20

B0088

Fig. 32

F1 Stroke rate at which the pump should operate with current I1

F2 Stroke rate at which the pump should operate with current I2

Plot a diagram similar to the one above - with values for (I1,

F1) and (I2, F2) – so that you can set the pump control as

required.

Using these processing types, you can control a metering pump using the

current signal as shown in the diagrams below.

Lower sideband:

The symbol

appears on the LCD screen. Below I1, the pump works at

a rate of F1 - above I2 it stops. Between I1 and I2 the stroke rate varies

between F1 and F2 in proportion to the signal current.

I [mA]

I 1 I 2

0 20

a) b)

Fmax

B0089

I [mA]

I 1

I 2

0 20

Fmax

Fig. 33: Lower sideband, e.g. alkali pump

Upper sideband:

The symbol

appears on the LCD screen. Below I1, the pump is sta‐

tionary - above I2 the pump works at rate F2. Between I1 and I2 the stroke

rate varies between F1 and F2 in proportion to the signal current.

The smallest processable difference between I1 and I2 is 4 mA

I [mA]

I 1

I 2

0 20

Fmax

B0090

Fig. 34: Upper sideband, e.g. acid pump

Upper/lower sideband

Adjustment